From corporate offices and healthcare facilities to residential communities, warehouses and entertainment venues, California properties face very different security risks. A technology campus may need controlled access and visitor screening, while a retail centre may require uniformed guards, mobile patrols and rapid incident reporting.
Security companies also operate differently. Some concentrate on on-site guarding, while others combine personnel with video surveillance, remote monitoring, alarm response and access-control systems. The right provider should be selected according to the property, operating hours, threat level and need for armed or unarmed personnel.
The following companies were selected after considering their California presence, service range, industry experience, technology, specialised security capabilities and support for multi-location clients.
1. Allied Universal – Best Overall Security Company
Allied Universal has one of the largest security workforces and branch networks available to California organisations. Its history dates to 1957, and the company now operates in more than 100 countries with approximately 770,000 employees worldwide.
Its services extend beyond standard security guards. Clients can arrange vehicle and bicycle patrols, visitor management, executive protection, K-9 teams, emergency response, investigations, event security and security operations centre support. Electronic services include access control, video surveillance, intrusion detection, weapons detection and security robotics.
Allied Universal maintains offices across major California markets, including Irvine, Los Angeles, Oakland, Sacramento, San Diego, San Francisco and San Jose. This network is useful for businesses operating several properties that want a consistent security programme across the state.
Why Businesses Choose Allied Universal
Large organisations can obtain guards, mobile patrols, technology and specialist services through one provider. Its extensive California network also makes it easier to arrange regional supervision, additional staffing and support for properties in different cities.
- Official website: https://www.aus.com/
- Corporate Headquarters West: 450 Exchange, Irvine, CA 92602.
- California PPO licence: 14417.
2. Securitas – Best for Integrated Guarding and Technology
Securitas combines traditional security personnel with mobile patrol, remote surveillance and electronic protection. This makes it suitable for companies that do not want to depend entirely on guards stationed at every entrance or building.
Its on-site services include trained security officers, reception security and customised guarding. Mobile services cover patrols, alarm response and key management. The company also offers remote guarding, alarm monitoring, video surveillance, access control, fire and safety services and risk-intelligence support.
Securitas reports a local presence in every US state and operates more than 200 offices nationwide. California locations include Anaheim, Los Angeles, Sacramento, San Francisco, San Jose and other regional markets.
A business can therefore create a layered system. Guards may handle visitors and visible patrols during busy hours, while cameras and remote operators monitor quieter areas overnight.
Why Businesses Choose Securitas
The company’s strongest advantage is the connection between personnel and technology. A client can combine on-site officers, mobile patrols, electronic systems and remote monitoring instead of managing several unrelated vendors.
- Official website: https://www.securitasinc.com/
- Los Angeles office: 1055 Wilshire Boulevard, Suites 1600, 1610, 1650 and 1680, Los Angeles, CA 90017.
3. GardaWorld Security – Best for Multi-Site Corporate Security
GardaWorld supports companies that need security across offices, construction sites, logistics facilities, data centres, healthcare properties and other commercial locations. Its California branch network covers Northern and Southern California, giving larger clients access to regional teams.
The company supplies security personnel, surveillance technology, crowd management and operational-risk services. It can also coordinate specialised support through affiliated operations such as Crisis24 for risk management, BEST for crowd and event services, and ECAM for remote video monitoring.
Industries served include commercial real estate, construction, banking, government, healthcare, education, manufacturing, logistics, energy, ports and residential communities. Security programmes are developed according to the site rather than relying on one standard guard package.
GardaWorld has California offices in Anaheim, Emeryville, Los Angeles, Ontario, Sacramento, San Diego and San Jose. This distribution can support businesses with facilities in several parts of the state.
Why Businesses Choose GardaWorld
GardaWorld is particularly useful when a company needs more than routine lobby security. Guarding can be combined with crowd control, remote surveillance, risk intelligence and services for complex corporate environments.
- Official website: https://www.garda.com/
- Los Angeles office: 3800 Barham Boulevard, Suite 410, Los Angeles, CA 90068.
4. Inter-Con Security – Best for Government, Transit and High-Risk Assignments
Headquartered in Pasadena, Inter-Con Security has developed a strong position in assignments where training, discretion and carefully managed security procedures are especially important. The family-owned company reports a workforce of more than 40,000 employees across the Americas and Africa.
Its services include armed and unarmed guards, executive protection, K-9 teams, off-duty officers, event security, investigations, fire and life-safety support, screening, access control and security operations centres. Technology and specialised training can be incorporated into each programme.
Inter-Con serves aviation, government, mass transit, financial institutions, entertainment, healthcare, energy, technology, logistics and high-net-worth clients. Its dedicated-service model is designed for organisations that require customised recruiting, training and supervision rather than guards drawn from a general shared pool.
The company was recognised as Outstanding Contract Security Company at the 2025 Global Security Exchange OSPAs.
Why Organisations Choose Inter-Con
Inter-Con is a strong candidate for sensitive facilities, public infrastructure and assignments requiring executive protection or armed personnel. Its Pasadena headquarters also gives it a genuine California base rather than only a regional branch.
- Official website: https://icsecurity.com/
- Global headquarters: 210 South De Lacey Avenue, Pasadena, CA 91105.
5. Bay Alarm – Best for Alarm, Video and Access-Control Systems
Bay Alarm is the most suitable company in this ranking for homeowners, small businesses and commercial properties seeking electronic security with professional monitoring. Founded in 1946, the California company entered its 80th year of operation in 2026.
Its services include burglar alarms, live video monitoring, surveillance cameras, access control, fire alarms and 24-hour monitoring. Businesses can also arrange security agents for perimeter protection, on-site guarding and alarm response.
The company operates throughout California, with locations serving Santa Clara, South San Francisco, Hayward, Petaluma, Concord, Sacramento, Stockton, Redding, Visalia, Los Angeles, Ventura, San Diego, Orange County and the Inland Empire.
Bay Alarm can design a system around doors, windows, parking areas, restricted rooms and outdoor spaces. Remote video services may help operators identify suspicious activity before sending an agent or contacting emergency services.
Why Customers Choose Bay Alarm
Bay Alarm offers a practical balance between electronic equipment and human response. It is more accessible to residential and smaller commercial customers than companies mainly structured around large guarding contracts.
- Official website: https://www.bayalarm.com/
- Concord office: 5130 Commercial Circle, Concord, CA 94520.
- California licences: CSLB 880138 and ACO 28.
How to Select the Right Security Company
First determine whether the property needs guards, electronic security or a combination of both. A warehouse may require cameras, access control and mobile patrols, while a hospital or corporate campus may need permanent officers at several posts.
Request a written security assessment before agreeing to a contract. The proposal should explain the number of guards, hours, patrol frequency, supervision, uniforms, equipment, incident reporting and replacement procedures when an officer is absent.
Ask how guards are recruited, screened and trained for the particular property. Healthcare, schools, entertainment venues and industrial sites may require very different skills. Armed assignments should receive additional scrutiny because the company and individual officers must hold the appropriate California credentials.
Businesses should verify licences through the California Bureau of Security and Investigative Services. Insurance, workers’ compensation, escalation procedures and emergency contacts should also be confirmed before service begins.
FAQs
Q: Which security company is best in California?
A: Allied Universal is the strongest overall choice because of its large California network and wide range of guarding, technology and specialist services. Inter-Con may be more suitable for government or high-risk assignments, while Bay Alarm is a practical option for electronic security and monitoring.
Q: Can a California business hire armed security guards?
A: Yes, but armed personnel must have the required state registration and firearm permits. The security company should also hold the appropriate operating licence. Credentials should be verified through the California Bureau of Security and Investigative Services.
Q: What is the difference between a guard company and an alarm company?
A: A guard company supplies trained personnel for entrances, patrols, events or emergency response. An alarm company installs and monitors systems such as cameras, intrusion alarms, fire alarms and access control. Some companies provide both.
Q: How much does private security cost in California?
A: Pricing depends on location, required training, armed or unarmed status, overnight hours, supervision, vehicles and contract length. Businesses should compare detailed quotations rather than choosing solely by the lowest hourly rate.
Q: Do these companies provide residential security?
A: Bay Alarm directly serves residential customers with alarms, cameras and monitoring. Other companies may support gated communities, apartment developments, estates and homeowners’ associations, but many of their services are primarily designed for commercial and institutional clients.
